| Vocabulary | Summary |
| C library interface parsing words | |
| Short-circuiting logical operations | |
| Short-circuiting logical operations which infer the arity | |
| Combinators which infer arities | |
| Delegation and mimicking on top of the Factor object system | |
| Syntax for pictured partial application and composition | |
| First-class syntax | |
| Parsing words for defining help articles | |
| Syntax sugar for the Factor compiler's specializer hints facility | |
| Interpolating variable values into strings | |
| Invertible quotations | |
| Lazy lists | |
| Expression interpolation into sequence literals | |
| Efficient named local variables and lexical closures | |
| Utility for defining compiler transforms | |
| ML-style pattern matching | |
| Memoization | |
| Observable slots which can be composed in various ways | |
| Declarative EBNF language for writing PEG parsers | |
| Lazy thunks | |
| Additional shuffle words | |
| 'Generic words' that dispatch on XML tag names |
| Vocabulary | Summary |
| Utility to simplify tuple constructors | |
| Coroutines implementation | |
| Descriptive errors generated automatically for specially defined words | |
| Support for infix notation in Factor programs | |
| Haskell-style monads | |
| Experimental multiple dispatch implementation | |
| Partial continuations - breset/bshift |